I've read about a little Mac app called f.lux for a year or two, but never tried it out. It's supposed to alter the colours on your screen to make night-time viewing easier on the eyes. Two days ago, I decided to try it out.

It's not in the App Store. You can get it from the f.lux website and it's free. I installed it on one of my MacBooks at night and it smoothly changed the colours to an orangey tone. My eyes relaxed. Amazing. I worked with it, and ignored the strange orange hue and it was great. I put it on all my laptops. I even put it on my Mac Mini. Switching between the Mac Mini and my Linux became an exercise in shock. My eyes would relax looking at the Mac Mini orangeness, and then get shocked by the brightness of the Linux screen.

On their website, they talk about removing blue tones from the monitor at nighttime so the bright blue doesn't affect your sleep patterns later. It's great. While looking at the website, I realised they have a Linux version. If you want the latest version, you want to be running a Linux distro that has the apt-get software. Slackware doesn't. But they provide an earlier (late 2013) command line executable which does the same thing, so I went with that. Downloaded a tgz file, which when unzipped gave a single file - xflux. When I ran this, it wanted my location and I could enter latitude and longitude, or my zip code. I went with the zip code. Typed

xflux -z 23320

and it knew where I was, and that it was nighttime, and it brought my screen down to the orange tones. Lovely. I added that to my FVWM startup scripts so it will run at startup. I went to take a screenshot of the effect that f.lux has, but the screenshot captured the original screen, not the modified screen. So took photos of my screen for before and after shots.

Here we are with f.lux not running and it's about 5pm and it's dark outside:

And this is after f.lux is running and has stabilised and modified the tone of the screen.

Of course, right now, to me, with f.lux running, both images look the same. But tomorrow when f.lux allows normal blues to come through, they will look different. There might not appear to be too difference between them, but the reduction of blue really does relax the eyes and makes night-time viewing of the screen much easier.

Both nights that I had f.lux working on all my monitors, I had great sleep. This is probably confirmation bias, or auto-suggestion, and only two data points does not make a trend, but still, I had great sleep.

Anne uses her iPad all night long, and the bright blue tones just glare out at night and sometimes wake me. I looked to see if they have an iPhone or iPad version of f.lux and they do. But only for jail-broken devices. They need some private APIs that Apple don't open up, so they can't provide a legit iPad/iPhone app. And that's a real shame. That would help Anne with her sleep, and in consequence that would help my sleep too.